Diodes Incorporated FMMTH10TC

Overview

FMMTH10TC from ON Semiconductor is an NPN silicon planar RF transistor in SOT-23 package, designed for high-frequency amplification up to 650 MHz with low noise (3–5 dB at 500 MHz), 0.7 pF collector-base capacitance, and 25 V V_CEO, used in VHF/UHF receiver front-ends and IF amplifier stages.

For engineers reviewing the FMMTH10TC datasheet, FMMTH10TC pinout, FMMTH10TC application, or FMMTH10TC equivalent, key selection criteria include f_T stability across temperature, noise figure at 2 mA/5 V bias, C_cb matching for impedance tuning, and SOT-23 thermal derating above 25°C ambient.

Technical Context

This RF transistor employs a planar epitaxial structure optimized for VHF–UHF small-signal amplification. Its f_T of 650 MHz is specified at I_C = 4 mA, V_CE = 10 V, and f = 100 MHz, with typical C_cb = 0.45–0.65 pF at V_CB = 10 V and f = 1 MHz.

Noise figure is characterized at I_C = 2 mA, V_CE = 5 V, and f = 500 MHz, delivering 3–5 dB typical performance. The device operates within –55°C to +150°C junction temperature range and supports pulsed testing (300 µs width, ≤2% duty cycle) for transient gain validation.

Key Specifications

Pinout & Package

Supplied in JEDEC-standard SOT-23 (TO-236AB) plastic surface-mount package with gull-wing leads; thermal resistance R_θJA ≈ 250°C/W (typical, no heatsink).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN RF transistor applications.

Compared with MRF901T1 and BFR92A, FMMTH10TC offers balanced f_T/NF/C_cb performance with superior V_CEO margin-making it optimal for 12 V IF amplifiers needing reliability over extreme bandwidth.

Availability

FMMTH10TC is available at Aetrix Electronics and suitable for FM radio IF amplifiers, UHF wireless microphone preamps, VHF aircraft band receivers, and ISM band sensor transmitter drivers requiring stable component supply across extended temperature ranges.

Supply support for FMMTH10TC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

ON Semiconductor is a global semiconductor supplier specializing in power management, analog, sensors, and connectivity solutions for automotive, industrial, and communications markets.

FMMTH10TC belongs to ON Semiconductor's legacy RF bipolar transistor product line, engineered specifically for high-frequency, low-noise amplification in compact consumer and avionics receivers.

FAQ

What is the recommended bias condition for minimum noise figure?

The FMMTH10TC achieves its lowest noise figure (3 dB typ.) at I_C = 2 mA and V_CE = 5 V. Base bias must be stabilized with a 10 kΩ–47 kΩ resistor to ground and emitter degeneration (22–47 Ω) to maintain linearity and thermal stability under varying temperature conditions.

Can FMMTH10TC replace BFR90A in existing designs?

Yes, with minor layout review: both are SOT-23 NPN RF transistors, but FMMTH10TC has higher V_CEO (25 V vs. 20 V) and slightly lower f_T (650 MHz vs. 700 MHz). Matching networks may require re-tuning due to C_cb difference (0.65 pF vs. 0.45 pF).

Is Spice model support available for simulation?

Yes-ON Semiconductor provides verified SPICE parameter data for FMMTH10TC upon request, including Gummel-Poon model parameters extracted from measured S-parameters and DC curves, enabling accurate AC/DC and transient simulation in Cadence and LTspice.

How does thermal performance scale above 25°C ambient?

P_tot derates linearly: maximum allowable power drops by 2.64 mW/°C above 25°C. At 85°C ambient, P_tot is reduced to ~170 mW. Layout must include ≥25 mm² copper pour under the SOT-23 pad to maintain T_j < 150°C at full rated current.